Two fixes on the postgres telegraf fan-out path:
1. postgres.auth cmd.run leaked the password to the console because
Salt always prints the Name: field and `show_changes: False` does
not apply to cmd.run. Move the user and password into the `env:`
attribute so the shell body still sees them via $PG_USER / $PG_PASS
but Salt's state reporter never renders them.
2. so-minion's addMinion -> setupMinionFiles sequence removes the
minion pillar file and rewrites it from scratch, which wipes the
postgres.telegraf.* entries the reactor may have already written on
salt-key accept. Add a postgres.auth fan-out step to
orch.deploy_newnode (the orch so-minion kicks off after
setupMinionFiles) and require it from the new minion's highstate.
Idempotent via the existing unless: guard in postgres.auth.